surface

Description:

Trochiliopsis opaca (Pennard 1922), a colorless microthoracid ciliate synonymous with Trichopelma opaca (Kahl 1931). This genus contains one other species, T. australis. The rigid body of T. opaca is ovoid and strongly laterally compressed, the anterior curving ventrally into a small beak (seen in accompanying images). The right and left surfaces are ribbed longitudinally. This image is of the sparsely ciliated left surface (sometimes designated as dorsal). Two posterior cilia are seen. There is a kinety curving toward the ventral surface and a cluster of cilia near the oral aperture. Two of the large obliquely oriented extrusomes are seen in the central anterior half of the cell. T. opaca is bactivorous. From putrefying freshwater specimen containing decomposing filamentous algae collected near Boise, Idaho. Differential interference contrast.